746 Research Update: Converting a Field Cultivator for Row Crop Use (2000)

746 Research Update: Converting a Field Cultivator for Row Crop Use (2000)
Printed: April, 2000
ISSN 1188-4770,
Group 10(k)
Research Update
Converting a Field Cultivator for Row Crop Use
Find an old field cultivator and convert it for your new row crops!
Are you looking for ways to diversify
your farm production?
Many producers in Saskatchewan
are looking to row crops, and particularly
herbs and spices as alternatives, but
need cultivation equipment suited to
growing row crops. But you may not
need to buy new equipment – you may
be able to modify an inexpensive older
machine yourself.
Some degree of tillage is required
for herb and spice production, either due
to organic requirements or due to a lack of registered
herbicides. Some producers prefer the small single row
tillers or three-point hitch equipment more commonly
found in market gardens, while others would rather
use a larger cultivator. In either case, older hitch-drawn
cultivators are plentiful on the Prairies, and serve as
excellent candidates for conversion to row-crop use.
To find out more, PAMI contacted herb growers
to gather information on their use of tillage equipment
and to find older cultivators that had already been
converted into row crop machines.
At a Glance
Most older field cultivators are suitable for
modification for row cropping. Your specific needs
will be determined by the crops you grow and the
tractor power available.
Factors you’ll want to consider include row spacing
and row spacing flexibility, whether you need a
towed or tractor mounted unit, frame size and layout,
ease of leveling, ease of moving, removing, and
replacing shanks, overall machine condition, and the
robustness of the shanks.
You may also want to add some type of guidance
system to keep the machine on track, and prevent
shovels from wandering into crop rows.
Photo Source: Province of Saskatchewan Agricultural
Machinery Administration
Choosing a Cultivator
No one make of machine is necessarily better
suited to conversion then another. Growers must
assess their own situation regarding crops, conditions,
tractor to be used, availability of a second operator,
etc. and then evaluate the available cultivators to
determine how well suited they are for conversion.
Cultivator Mounting Position
Cultivators can be either drawn, front mounted or
three-point hitch mounted. What follows are some pros
and cons of each type.
Drawn Cultivators: Hitch movement and the
length of the drawbar can cause side to side movement
of the cultivator. This can be to the operator’s advantage
if guide wheels are used, allowing slight lateral shifts of
the machine to line up with the rows. Drawn cultivators
typically don’t need any hitch modifications.
However, a drawn cultivator is positioned far
behind the tractor operator’s position, making it hard to
see crop damage or make minor steering changes to
prevent crop damage. A cultivator steering mechanism
may be needed with either a second operator riding
on the cultivator or an automatic guidance system to
make tracking adjustments as the cultivator travels
down the rows.
Three-point Hitch Mounts: Farmers with threepoint hitch equipped tractors will appreciate having
the tillage tool closer to the operator’s position,
improving visibility and allowing more positive tracking
control. However, tractor steering corrections amplify
movement of rear mounted cultivators in the opposite
direction, threatening crop rows. Shorter cultivators
work better with these systems and depending on row
space, a single or double rank machine may be the
Front Mounted (Push Style): Mounting the
cultivator in front of the tractor and pushing it provides
the operator with good visibility and maneuverability
while cultivating (Figure 1), eliminating additional
guidance systems or a second operator. Although not
a traditional position for a pulled machine, the concept
appears to have merit, especially for the smaller size
of older cultivators.
Two concept drawings (Figure 1 and 2) have
been included to show some possibilities. Either a
push pole or a three-point lift device on the front of
the tractor could be used to control the cultivator. The
largest effective cultivator width will be a function of
tractor weight, as heavy forces from stones applied to
the outer ends of the cultivator may push the tractor
equipment. Do you use a single row seeder or multiple
row seeder with spacing that matches your cultivator?
If the row crop cultivator will be used for seeding by
adding a seed box on top, then tillage shanks with a
seed opener should be installed where needed. This
arrangement can also be used for marking rows when
seeding one row at a time. The tillage shovels can be
moved to the location of the seed rows and serve the
dual purpose of marking the field (Figure 4).
Figure 2. Push cultivator mounted in front of tractor.
Frame Size or Layout
Figure 1. Push cultivator mounted in front of tractor and connected
to the rear hitch point.
Determine Row Spacing
Determine the row space requirements for the
crops you are growing and will grow. Having moveable
shanks allows for maximum flexibility. Ask yourself if
the crop fills in towards the centre of the rows, and
how much you will need to adjust the shank or tool
width to accommodate this growth. Would a knockon style opener by justified? The crop row spacing
may need to be altered in the middle of the machine
to accommodate your tractor tire spacing (Figure 3).
This spacing may also be affected by your seeding
Page 2
Field cultivators were originally designed to be
strong enough to work the soil at row spaces of 12 in.
or less, with a full set of shovels. In row cropping you
will be using at most only 2/3 of the shanks, so frame
size or strength isn’t a big concern. Make sure at least
2/3 of the shanks and trips are in good shape.
Plugging between the shanks shouldn’t be a
problem with the wider row spacing required for row
crops, so either a three or four rank machine should
be fine. In some row crop cases a double rank or even
single rank tool bar can be used. Frame to ground
clearance may be a consideration if you are tilling a tall
crop, as is the case with multi-year herb crops (Figure
Frame width will be a consideration depending on
topography, machine leveling and whether it is drawn
or mounted directly on the tractor. Frame width, tool
type, cultivation depth and ground speed will all affect
tractor horsepower requirements (See the section
entitled Determining Horsepower Requirements).
Keeping Your Cultivator On Track
Tractor mounted cultivators, whether front or rear
mounted, are guided by steering the tractor. Simple
pointer type markers attached to the tractor can be
used to assist the driver in this process.
But keeping your tractor-drawn cultivator on track
in the field can be more difficult. When the cultivator
is towed behind the tractor there is some lag time and
difficulty ensuring tillage up to but not into the growing
Guidance systems can help operators get close
to the crop and reduce the need for hand weeding.
Keep reading to find out more about different control
systems to keep a towed cultivator in line.
Guide Wheels
Figure 3 (left): Cultivating with an 18 in row spacing on a 12 foot
machine. Figure 4 (right): Tillage shovels can be moved to the
location of the seed rows and serve the dual purpose of marking
the field.
Guide wheels are usually found on market garden,
three-point hitch style equipment, and in principle
should work well on towed machines also.
Guide wheels adjust cultivator tracking by riding
in guide furrows or against ridges usually made at
seeding. These systems allow the cultivator to move
sideways, in relation to the tractor, within the limits of
the hitch. By leaving the drawbar free to swing from
side to side, the tractor simply pulls the cultivator and
is only used to guide it in a general direction.
Encountering rocks, wind and rain erosion may
affect guide wheel performance with a towed cultivator,
though we did not observe any of these problems. A
guide wheel system may be more suited to crops that
are harvested yearly rather than crops that require a 2
or 3 year growing cycle, as ridges or furrows created
during seeding will disappear over time and provide
less direction to the cultivator. In addition, erosion, plant
roots and other factors will become more prominent
over time and may negatively affect cultivator tracking.
The Williams Tool System uses guide wheels as a way
of manually guiding the cultivator (Figure 6).
Figure 5. Crop height is an important consideration when converting
a field cultivator to row crop use.
Some additional considerations for machine
selection include:
How easy is the machine to level front to back
and side to side, and are all the adjustments still
Are the remaining shanks still fairly
Ease of movement of the shanks, including sliding
from side-to-side and removal and replacement on
the frame, are major considerations especially if
you are working in different crops and row spacing.
How heavy are the shanks? Lighter shanks may
wander more due to side stone impact or when a
shank is working against a soil ridge.
Figure 6. The Williams Tool System uses guide wheels as a way of
manually guiding the cultivator. Market Farm Implement Catalogue
photo, used by permission.
Hydraulic Guidance with Operator Assist
Charlie Coleman of McAuley, Manitoba, and row
crop farmers in the United States have adapted and
used variations of hydraulic guidance systems with tow
behind cultivators. An operator sitting on the cultivator
operates a hydraulic valve, which controls a cylinder
connected to the swinging draw bar. By adjusting the
valve, the operator can move the draw bar left or right,
adjusting the cultivator to accommodate closer tillage
to the crop (Figure 7).
Figure 7. Operator Steered Cultivators are safer if the operator is
positioned at the rear of the cultivator, facing direction of travel.
This modification is achieved by mounting a
hydraulic cylinder underneath the tractor, approximately
halfway between the draw pin and the front mounting
pin on the drawbar. The cylinder rod end is positioned
on the drawbar where the cylinder stroke in and out
is matched to or greater than the sideways swing of
the drawbar. The back of the cylinder is then mounted
perpendicular to the draw bar when the drawbar is in
its ‘straight back’ position.
A hydraulic 2-way valve is quick coupled into one
of the remote circuits of the tractor. The hydraulic
valve must be matched to either the open centre or
closed centre system of the tractor. A standard 4 in.
agricultural cylinder with an 8 in. stroke will work fine. A
flow control valve on the hydraulics may be required to
reduce the reaction speed of the cylinder to eliminate
rapid drawbar whipping. The cultivator operator, by
operating the valve, steers the cultivator to ensure
proper tillage tracking. The hydraulics required for this
system cost about $300 plus hoses. A basic layout of
the hydraulic guidance system appears in Figure 8.
When using this system it’s easiest for the cultivator
operator to line up the cultivator with a marker located
above one row, rather than line up a shank with a
buried shovel that is travelling close to the crop. The
marker can be anything that hangs above one row of
crop to aid in positioning. A disk used to hill the crop is
easier to keep in line, as it is more visible than a shovel.
The seat on the cultivator should be located at the rear
of the machine for safety and ease of operation. The
tractor operator then need only concentrate on tractor
travel between rows.
Readers should be aware that these systems
pose some risk to the operator from dust, falling off the
machine, or potential injury due to shank breakage.
Minimize hazards by carefully positioning the seat,
using a seat belt, and wearing a suitable dust mask.
Figure 8. Concept for operator assist, hydraulically controlled
guidance system.
Figure 9. A guidance system using wire or plastic wands that run
along the soil surface near the base of the plant. The wands rotate
around a pivot point when contacting the crop, activating a micro
switch and sending a signal to a hydraulic cylinder used to steer the
unit. (Source: Steel in the Field,© 1997, The Sustainable Agriculture
Network, used by permission)
Automatic Guidance Systems
The automatic guidance system eliminates the
need for a second operator on the cultivator. These
systems use sensors to control the movement of the
cultivator by either moving the hitch or by steering
the tractor, and can also be used for guidance during
One type uses wire or plastic wands that run along
the soil surface near the base of the plant. The wands
rotate around a pivot point when contacting the crop,
activating a micro switch and sending a signal to a
hydraulic cylinder used to steer the unit (Figure 10).
However, residue, protruding dirt or weed growth can
compromise accurate row crop sensing.
Figure 10. Tri-R Innovation System steers the tractor for seeding
and cultivating (Planting operation shown here) Photo Source:
Company Literature.
Figure 12. Tri-R Innovation System steering control feedback sensor
mounts onto steering axle. Photo Source: Company Literature
Figure 13. The Smart Hitch Guidance System steels the cultivator
from the rear of the tractor. Photo Source: Smart Hitch photo, used
by permission.
Another system uses a sensor mounted at the front
of the cultivator that straddles the crop, controlling the
direction by sensing changes in the dirt height near
the crop row. Sophisticated systems allow you to
adjust the sensitivity so the system doesn’t overreact
to foreign obstacles. See Figures 11 - 15 for a pictorial
overview of automated guidance systems.
None of the mentioned guidance systems, manual
or automatic, have been evaluated by PAMI, and PAMI
is not endorsing the use of any particular system.
Producers should investigate cost, performance and
reliability before purchasing of these systems. See the
section entitled Manufacturer’s Addresses for contact
Figure 14. The Smart Hitch Guidance System mates to a steering
mechanism on the cultivator. Photo Source. Western Producer/
Michael Raine. Used by permission.
Figure 11. Tri-R Innovation System steels the tractor for seeding
and cultivating (Cultivating operation shown here). Photo Source:
Company Literature
While towed cultivators can be modified for threepoint hitch or front attachment (and there may be
advantages to doing this), we were not able to find
any examples of such conversions. Expect a certain
amount of trial and error work if you are attempting a
three-point hitch or front-mount conversion.
Towed cultivators have been successfully adapted
for row crop use in many instances. Your need for a
guidance system will depend on your individual needs.
Herbs and Spices in
Fast Facts:
The Saskatchewan Herb and Spice Association
(SHSA) has about 300 members.
Herb and spice production is just beginning to
become mechanized, but is still a labour intensive
operation. Machinery is being developed at the
There are about thirty different varieties of
medicinal plants grown in Saskatchewan. These
include three of the nine varieties of echinacea.
Currently most commercial echinacea production
is angustifolia.
Some of the other herb varieties grown are
St. John’s wort, valerian, burdock, fireweed or
willowherb, milk thistle, basil, chamomile and
Extracts of fireweed are used in the cosmetic
industry. Fytokem contracts both wildcrafted and
commercial grown production.
For more information, contact:
Saskatchewan Herb and Spice Association
Box 124
Sintaluta Sask. S0G 4N0
Ph: 1-306-727-4917,
Fax: 1-306-727-2226
Determining Power
Draft Characteristics
Over the years, PAMI has measured the draft
requirements of numerous full-scale cultivators in
various field conditions. These measurements can be
used to determine average draft requirements.
Draft requirements for the same cultivator in
the same field may vary by as much as 30% in two
different years due to changes in soil conditions.
Variations in soil conditions affect draft much more
than variations in machine brand, making it difficult
to measure any significant draft differences between
brands of cultivators.
PAMI’s averaged results are a useful tool in
determining tractor size requirements.
Recommended Tractor Size
Tables 1 and 2 show the tractor PTO power
required to pull cultivators in various conditions at the
given depths and speeds. Tractor power requirements
have been adjusted to include a tractive efficiency
of 80% in primary and 70% in secondary tillage and
represent a tractor operating at 80% of maximum PTO
power on a level field. These power requirements can
be used along with the maximum PTO ratings, as
determined by Nebraska tests or as presented by the
tractor manufacturer, to select the appropriate tractor.
Higher power will be required in hills or in heavy
soils. Cultivators with marked differences in spacing,
number of rows, or configuration may require more or
less power.
Table 1. Tractor PTO Power Per Unit Width [hp/ft [kW/m]] Required
in Primary Tillage
SPEED - mph (km/h)
Table 2. Tractor PTO Power Per Unit Width [hp/ft [kW/m]] Required
in Secondary Tillage
SPEED - mph (km/h)
Recommended tractor size may be determined
by selecting the required horsepower per foot from
the appropriate table and multiplying by the amount
of tillage width (not crop width) of the cultivator. For
example, in primary tillage at 2 in (50 mm) and 4 mph
(6.4 km/h), 2.7 hp/ft (6.6 kW/m) is required. Therefore,
for a 12 ft (3.6 m) cultivator in those conditions,
33 PTO hp (25 kW) is recommended.
PAMI wishes to thank the Agriculture Development
Fund of Saskatchewan Agriculture and Food for its
support in making this project possible.
Manufacturers Guide
Manual Guidance Systems
Alloway Ind,
1330 43rd ST NW
Fargo, ND 58102
Phone: (800) 289-3067
Fax: (701) 282-7043
Canadian DealerMilliken Farm Supplies Ltd.
5614 64 St
Taber, AB T1G 1Y8
Phone: (403) 223-4437
Fax: (403) 223-3411
Kroeker Machinery Sales
PO Box 1026
Winkler, MB R6W 4B1
Phone: (204) 239-4947
Bezzerdies Bros. Inc,
PO Box 211
Orosi, CA 93647
Phone: (559) 528-3011
Fax: (559) 528-9343
Canadian DealerJohn C Graham Co Ltd.
88 Erie St N
Leamington, ON N8H 2Z6
Phone: (519) 326-5051
Bush Hog Corp.
2501 Griffin Ave
Selma, AL 36702-1039
Phone: (334) 872-6261
Fax: (334) 872-6262
Saskatchewan Dealers –
Ferre’ Farm Equipment
601 Park Rd
Zenon Park, SK
Phone: (306) 767-2202
Harper Implements (1985) Ltd.
120 Simpson Ave
Birch Hills, SK
Phone: (306) 749-3588
Fennig Farm Equip Ltd.
4301-52nd St
Lloydminster, SK
Phone: (306) 825-4871
Nykolaishen Farm Equip Ltd.
Hwy 8 South
Kamsack, SK
Phone: (306) 542-2411
Oxbow Farm Centre Ltd.
Hwy 18 West
Oxbow, SK
Phone: (306) 483-2244
Armstrong Imp (1993) Ltd.
625 N Railway St W
Swift Current, SK
Phone: (306) 773-7281
Farm World Equipment Ltd.
Kinistino, SK
Phone: (306) 864-2522
Dupont Holdings Ltd.
North Service Rd, Hwy 1
Swift Current, SK
Phone: (306) 773-8682
Farmfax Mgmt System, Inc.
Highway #6 North
Raymore, SK
Phone: (306) 746-2271
Sagal Bros Sales Ltd.
1030 N Service Rd
Moose Jaw, SK
Phone: (306) 692-7844
Agratec Int’l Ltd.
Hwy 318
Carnduff, SK
Phone: (306) 482-3377
Triod Supply (NB) Ltd.
2621 98th St
North Battleford, SK
Phone: (306) 445-1200
Hwy 14
Perdue, SK
Phone: (306) 237-4272
Cropper Motors Inc.
Hwy #6 North
Naicam, SK
Phone: (306) 874-2011
Wagar Farm Equipment Ltd.
Hwy 9 & 49 West
Sturgis, SK
Phone: (306) 548-2966
Glenmor Grain Systems Ltd.
Old Hwy 2 South
Prince Albert, SK
Phone: (306) 764-2325
Ofe Farm Equip Ltd.
Hwy 15 West
Outlook, SK
Phone: (306) 867-8328
Hibbard Equip Ltd.
Main Street
Minton, SK
Phone: (306) 969-2133
Wawota Garage Ltd.
Hwy 28 East
Wawota, SK
Phone: (306) 739-2377
Canadian DealerApollo Distributing Corp
Highway 1 E
Emerald Park, SK
Phone: (306) 781-2644
Fax: (306) 781-2599
Automatic Equipment
One Mill Road, Industrial Park
Pender, NE 68074
Phone: 402) 385-3220
FSH Inc.
PO Box 654
Henderson, NE 68371
Phone: (402) 723-4468
Lincoln Creek Mfg.
RD 1 Box 41
Phillips, NE 68865
Phone: (402) 886-2483
Fax: (402) 886-2274
Market Farm Implement
257 Fawn Hollow Road,
Friedens, PA 15541
Phone: (814) 443-1931
Fax: (814) 445-2238
Sukup Mfg. Co.
Box 677
Sheffield, IA 50475-0677
Phone: (515) 892-4222
Fax: (515) 892-4629
Roll-A-Cone Mfg, & Dist.
Box 23 R2
Tulia, TX 79088
Phone: (806) 668-4722
Fax: (806) 668-4725
Canadian Independent
Jim Armstrong
Phone: (519) 657-1787
Straw Track Mfg. Inc.
PO Box 871
Whitewood, SK S0C 5C0
Phone: (306) 735-2208
Fax: (306) 735)2349
Email: [email protected]
Sprayrite Mfg. Co.
PO Box 3289 West
Helena, AR 72390
Phone: (870) 572-6737
Fax: (870) 572-6730
Automatic Guidance
4830 River Green Parkway
Duluth, GA 30136
Phone: (770) 813-9200
Fax: (770) 813-6038
Canadian DealerAvenue Farm Machinery Ltd.
1521 Sumas Way Box 369
Abbotsford, BC V2S 4N9
Phone: (604) 864-2665
Buffalo Farm Equipment
PO Box 848
Columbus, NE 68602-0848
Phone: (402) 564-3244
Fax: (402) 562-6112
Tri-R Innovations, Inc.
628 S. Sangamon Ave.
Gibson City, IL 60936
Phone: (217) 784-8495
SUNCO Marketing (AcuraTrak)
4320 Rodeo Rd
North Platte, NE 69101-1007
Phone: (308) 532-2146
Email: [email protected]
Canadian DealerGrower Supply Ltd.
401 1st St N
Vauxhall, AB T0K 2K0
Phone: (403) 654-2223
Fax: (403) 654-2414
Prairie Agricultural Machinery Institute
Head Office: P.O. Box 1900, Humboldt, Saskatchewan, Canada S0K 2A0
Telephone: (306) 682-2555
3000 College Drive South
Lethbridge, Alberta, Canada T1K 1L6
Telephone: (403) 329-1212
FAX: (403) 328-5562
Test Stations:
P.O. Box 1060
Portage la Prairie, Manitoba, Canada R1N 3C5
Telephone: (204) 239-5445
Fax: (204) 239-7124
P.O. Box 1150
Humboldt, Saskatchewan, Canada S0K 2A0
Telephone: (306) 682-5033
Fax: (306) 682-5080
This report is published under the authority of the minister of Agriculture for the Provinces of Alberta, Saskatchewan and Manitoba and may not be reproduced in whole or in part without the prior
approval of the Agricultural Technology Centre or The Prairie Agricultural Machinery Institute.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF